🚀 go-pugleaf

| Hello,
| Can anyone explain me strange behaviour on SPARC 
| for following function:
| 
| void pp( int *i )
| {
|   int j;
| 
|   pp( &j );
| }
| 
| when compiled with -O2 (-O4 for cc) by
| gcc uses about 120 bytes on stack for each call,
|  cc ...        104 ...
| acc ...        112 ...
| 
| when in reality (if I'm not mistaken) all we need is:
| 
| Instruction pointer,
| Stack pointer,
| Argument "i"
| Local variable "j"
| -------------------
| = 16 bytes !!
| 
| why is WINDOWSIZE in gcc 20, and in cc 16 ?
| 
| Thanks, Igor

I don't know for sure, but I'll guess gcc is be default using the
extra 4 bytes on the stack to hold the frame pointer.  You can ask gcc
to not do this.

See the info page for gcc:

`-fomit-frame-pointer'
     Don't keep the frame pointer in a register for functions that
     don't need one.  This avoids the instructions to save, set up and
     restore frame pointers; it also makes an extra register available
     in many functions.  *It also makes debugging impossible on some
     machines.*

     On some machines, such as the Vax, this flag has no effect, because
     the standard calling sequence automatically handles the frame
     pointer and nothing is saved by pretending it doesn't exist.  The
     machine-description macro `FRAME_POINTER_REQUIRED' controls
     whether a target machine supports this flag.  *Note Registers::.

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